d = {"中国": "北京", "美国": "华盛顿"}
print(d["美国"])
d["美国"] = "123"
print(d["中国"])
ls = list()
st = set()
st.add(1)
st.add(1)
ls.append(1)
ls.append(1)
de = {}
print(type(de))
print(type(ls))
print(type(st))
print(ls)
print(st)
print(d["美国"])
print(d.items())
d.update({"美国": "华盛顿"})
print(d)
print(d.keys())
print(d.values())
keys = d.keys()
for i in keys:
    print(i)
items = d.items()
for i in items:
    print(i)
print("c" in d)
d["法国"] = "巴黎"
print(d)

